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$539+ Cheap flights from London (LON) to Seattle (SEA)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/20. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
Aug 5 — Aug 121
Tue 8/5
Tue 8/12
1 adult, Economy
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Cheapflights Tip: The best prices from London to Seattle/Tacoma Intl are usually found in January or March, booked 44 days in advance, depart on a Wednesday or Monday and return on a Tuesday

Cheap flight deals from London to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from London (LON) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated July 31, 2025.

Round-trip from

$650
(Kiwi.com)

One-way from

$539
(Kiwi.com)

Popular in

July

Cheapest in

January

Average price

$950

Good round-trip deal

$743 or less

Good one-way deal

$802 or less
From London (LON) to Seattle/Tacoma Intl
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One-way flight from London (LON) to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 15% potential increase in price ($132 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($19 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Price to beat on a round-trip flight from London (LON) to Seattle/Tacoma Intl.
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Price to beat on a one-way flight from London (LON) to Seattle/Tacoma Intl.
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Find flight deals from London to Seattle

Cheapest flights from London to Seattle
Explore the most affordable flight options available from London to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

This Kiwi.com deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/86:25 amSTN - SEA
1 stop19h 25mMultiple Airlines
Tue 9/237:35 pmSEA - STN
1 stop17h 40mMultiple Airlines
Deal found 7/30$650
This ChecknFly deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure ChecknFly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/279:50 amLHR - SEA
Nonstop9h 45mFinnair
Thu 9/116:00 amSEA - LHR
1 stop19h 05mFinnair
Deal found 7/30$650
This lol.travel deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure lol.travel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/81:25 pmLHR - SEA
Nonstop10h 05mVirgin Atlantic
Mon 9/225:35 pmSEA - LHR
Nonstop9h 45mVirgin Atlantic
Deal found 7/31$651
This The Travel House deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/231:00 pmLGW - SEA
1 stop12h 50mIcelandair
Mon 8/2511:30 pmSEA - LGW
1 stop31h 10mIcelandair
Deal found 7/30$652
This Cheapflightsfares deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/104:30 pmLHR - SEA
Nonstop9h 50mBritish Airways
Mon 9/158:20 pmSEA - LHR
Nonstop9h 20mBritish Airways
Deal found 7/31$652
This Kiwi.com deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/11:05 pmLGW - SEA
1 stop16h 46mMultiple Airlines
Tue 10/1410:55 pmSEA - LGW
1 stop23h 25mMultiple Airlines
Deal found 7/31$654
This Austrian Airlines deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Austrian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/286:00 amLHR - SEA
2 stops22h 54mAustrian Airlines
Mon 2/238:00 amSEA - LHR
2 stops39h 55mAustrian Airlines
Deal found 7/30$654
This The Travel House deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/276:05 pmLHR - SEA
2 stops51h 45mScandinavian Airlines
Wed 9/104:00 pmSEA - LHR
2 stops21h 35mScandinavian Airlines
Deal found 7/29$655
This Gotogate deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/19:30 amLHR - SEA
1 stop19h 15mAir Canada
Mon 9/1510:00 amSEA - LHR
2 stops15h 35mAir Canada
Deal found 7/30$657
This SWISS deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure SWISS is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/169:25 amLCY - SEA
2 stops17h 11mSWISS
Tue 9/3010:50 amSEA - LCY
2 stops22h 40mSWISS
Deal found 7/30$658
This Expedia deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/279:50 amLHR - SEA
Nonstop9h 45mMultiple Airlines
Wed 9/103:00 pmSEA - LHR
1 stop13h 15mMultiple Airlines
Deal found 7/30$658
This Mytrip deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/136:15 pmLCY - SEA
1 stop25h 55mLufthansa
Mon 11/172:00 pmSEA - LCY
1 stop19h 40mLufthansa
Deal found 7/29$659

Cheapflights Fare Finder

 
Customize your flight search to find flights from London to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 31, 2025.
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

London

Fly to

Seattle

Route

Depart

Return

Price

LondonSeattle

STN - SEA

STNSEA

London Stansted

Mon 9/8

6:25 am-5:50 pm

1 stop19h 25m

Seattle/Tacoma Intl

Tue 9/23

7:35 pm-9:15 pm

1 stop17h 40m

$650

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 8/27

9:50 am-11:35 am

Nonstop9h 45m

Seattle/Tacoma Intl

Thu 9/11

6:00 am-9:05 am

1 stop19h 05m

$650

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 9/8

1:25 pm-3:30 pm

Nonstop10h 05m

Seattle/Tacoma Intl

Mon 9/22

5:35 pm-11:20 am

Nonstop9h 45m

$651

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Sat 8/23

1:00 pm-5:50 pm

1 stop12h 50m

Seattle/Tacoma Intl

Mon 8/25

11:30 pm-2:40 pm

1 stop31h 10m

$652

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 9/10

9:50 am-11:35 am

Nonstop9h 45m

Seattle/Tacoma Intl

Mon 9/15

1:30 pm-6:50 am

Nonstop9h 20m

$652

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 9/1

9:30 am-8:45 pm

1 stop19h 15m

Seattle/Tacoma Intl

Mon 9/15

7:15 am-9:35 am

1 stop18h 20m

$654

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

Wed 10/1

1:05 pm-9:51 pm

1 stop16h 46m

Seattle/Tacoma Intl

Tue 10/14

10:55 pm-6:20 am

1 stop23h 25m

$654

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Wed 8/27

6:05 pm-1:50 pm

2 stops51h 45m

Seattle/Tacoma Intl

Wed 9/10

4:00 pm-9:35 pm

2 stops21h 35m

$655

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

Mon 9/1

7:45 am-8:42 pm

2 stops20h 57m

Seattle/Tacoma Intl

Mon 9/15

10:55 am-8:20 am

1 stop13h 25m

$657

LondonSeattle

LCY - SEA

LCYSEA

London City

Tue 9/16

9:25 am-6:36 pm

2 stops17h 11m

Seattle/Tacoma Intl

Tue 9/30

10:50 am-5:30 pm

2 stops22h 40m

$658

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/29

Showing 1-10 of 41 results
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The best insider tips for London to Seattle flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your London to Seattle trip
Airports
LHR

For a smooth departure from Heathrow, ensure all liquids are in one small bag to avoid lengthy security checks.

Read more about LHRby Ramsey Qubein
SEA

Use the Link light rail from SEA to downtown Seattle for an affordable, 40-minute journey with ample luggage space.

Read more about SEAby Brandon Schultz
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on LHR

Ramsey Qubein

Ramsey Qubein

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

Best time to book a flight from London to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from London with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from London to Seattle

How far ahead should I book a flight from London to Seattle?

Use this chart to determine the optimal time to book a round-trip flight from London to Seattle. Price data was last updated on July 25, 2025.

To ensure you get the cheapest price possible for a flight from London to Seattle, you should look to book at least 44 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from London to Seattle?

Currently, January is the cheapest month in which you can book a flight from London to Seattle (average of $238). Flying from London to Seattle in June is currently the most expensive (average of $389). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from LON to SEA?

Find hourly flight availability from London to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 31, 2025.

One of the essential ways to save on airfare from London to Seattle is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 6% on airfare.

What is the cheapest day to fly from London to Seattle?

Use this chart to determine the cheapest time to fly round-trip from London to Seattle. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their London to Seattle flight should consider departing on Monday evenings when fares are most often at their lowest. Friday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from London to Seattle

Explore weekly flight availability from London to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated July 31, 2025.

The most flights from LON to SEA are scheduled on a Monday (22 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (11 on average).

How much does it cost to fly round-trip from London to Seattle?

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated July 31, 2025.
See what other customers who have flown with Delta, Austrian Airlines, and Finnair from London to Seattle have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,981 reviews

Entertainment

7.9

Boarding

8.2

Food

7.3

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Delta
8.0
Very good
7,981 reviews
Delta
8.0
Very good
7,981 reviews

Entertainment

7.9

Boarding

8.2

Food

7.3

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Austrian Airlines
7.6
Good
823 reviews
Delta
8.0
Very good
7,981 reviews

Entertainment

7.9

Boarding

8.2

Food

7.3

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Finnair
7.6
Good
1,316 reviews
Delta
8.0
Very good
7,981 reviews

Entertainment

7.9

Boarding

8.2

Food

7.3

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
Air France
7.5
Good
1,465 reviews
Delta
8.0
Very good
7,981 reviews

Entertainment

7.9

Boarding

8.2

Food

7.3

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.
SWISS
7.5
Good
1,686 reviews
Delta
8.0
Very good
7,981 reviews

Entertainment

7.9

Boarding

8.2

Food

7.3

Overall

8.0

Crew

8.5

Comfort

7.9

Reviews

1 / 20
8.0
Excellent

Michael,Jul 2025

AMS - ATL

Overall it was great experience, with the exception of snack food. The food offered in two main meals was just fine but for the mid-flight snack, the only option was a large cookie, too sweet and high sugar content. Snacks at the back of the plane were also mainly sweets. There was one nice baked cheddar option but it quickly ran out.

Related info for your journey

Find useful and relevant information for your journey from London to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from London?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from London to Seattle. 6 airlines have flights to Seattle/Tacoma Intl from London on a regular basis. Booking flights from London to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 18 inbound flights from London per day.

  • What are the cheapest airlines flying from London to Seattle round-trip?

    Cheapflights users have booked flights from London to Seattle round-trip from $650. Other airlines that can offer you cheap pricing are Virgin Atlantic, from $651, and Icelandair, from $652. Finnair is currently priced 12% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from London to Seattle one-way?

    One-way options have recently been found by users for as low as $543 on Aer Lingus. Other airlines that offer cheap prices include WestJet from $554 and Icelandair from $602 one-way.

  • What are the most popular routes from London to Seattle?

    Most travelers choose London Heathrow - Seattle/Tacoma Intl, London Gatwick - Seattle/Tacoma Intl or London City - Seattle/Tacoma Intl when deciding on the best route from London to Seattle.

  • What are the most reliable airlines from London to Seattle?

    The top 3 most reliable airlines when flying from London to Seattle are Scandinavian Airlines (97%), KLM (94%) and Air France (94%).

  • What are the cheapest flights from London to Seattle?

    While on average a flight from London to Seattle is generally $2,627, our data shows the cheapest flight currently is $676. When looking at the most popular route, (London Heathrow - Seattle/Tacoma Intl), you can expect to pay $535 for that flight.

  • Can I find deals for flights from London to Seattle that include hotel bookings?

    Yes. In addition to deals on London to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from London to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Seattle.

  • Can I find deals for business class flights from London to Seattle?

    Yes. Cheapflights offers flight deals from London to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from London to Seattle?

    Currently, January is the cheapest month in which you can book a flight from London to Seattle (average of $238). Flying from London to Seattle in June is currently the most expensive (average of $389). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
SeaTac
Tukwila
Tacoma
Ocean Shores
Lakewood
Lynnwood
Lacey
Leavenworth
Renton
Olympia
Puyallup
Kent
Cle Elum
Chehalis
Kirkland
Issaquah
Aberdeen
Shoreline
Federal Way
Shelton

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for London to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from London to Seattle

Discover the top 6 airlines that operate flights from London to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest$402Average$787FlexibilityNo cancel feeOn-time76%
British AirwaysCheapest$560Average$765FlexibilityNo cancel feeOn-time70%
IberiaCheapest$575Average$781FlexibilityNo cancel feeOn-time77%
Virgin AtlanticCheapest$594Average$918FlexibilityNo cancel feeOn-time72%
American AirlinesCheapest$620Average$813FlexibilityNo cancel feeOn-time71%
DeltaCheapest$632Average$852FlexibilityNo cancel feeOn-timeN/A

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